Control device for the power units



y 1952 H. A. ALEXANDERSON ETAL Re. 23,490

CONTROL DEVICE FUR THE POWER UNITS OF AIRCRAFT Original Filed May 29, 1945 HOWARD A. ALEXANDERSON ROBERT Z. HAGUE mTomvE Reissued May 20, 1952 CONTROL DEVICE FOR. THE POWER UNITS OF AIRCRAFT Howard A. Alexanderson, Hohokus, and Robert Z. Hague, Oradell, N. J., assignors to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Original No. 2,538,777, dated January 23, 1951,

Serial No. 12,784, March 3, 1948, which is a division of Serial No. 596,472, May 29, 1945. Application for reissue June 27, 1951, Serial No.

7 Claims.

The present application is for a reissue of U. Patent No. 2,538,777, granted January 23, 1951, on an application Serial No. 12,784, filed March 3, 1948, as a division of U. S. application Serial No. 596,472, filed May 29, 1945, by Howard A. Alexanderson and Robert Z. Hague and relates to improved control devices for the power units of aircraft.

An object of the invention is to provide a novel linkage arrangement for alternately effecting automatic or manual control.

Another object of the invention is to provide a novel linkage for effecting manual control upon failure of the Operating medium for the automatic control.

Another object of the invention is to provide novel linkage means for effecting direct manual control upon failure of a normally operative automatic motor means.

Another object of the invention is to provide a novel linkage arrangement, including a walking beam operative in one sense for interconnecting a manually operated shaft and a second shaft to be controlled, and the walking beam operative in a second sense for permitting movement of said second shaft by an automatic motor means free of said first mentioned shaft, and a means for locking said walking beam from the latter operation upon failure of the operating medium for the motor means.

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying drawing wherein one embodiment of the invention is illustrated by way of example.

The drawing is a diagrammatic View of the novel linkage arrangement for effectin manual control upon failure of the operation medium for automatic control.

Referring to the drawing, a control lever 3 is keyed to a main control shaft 4 which extends into a control unit indicated in the drawing by the letter A. The control lever 3 is connected by a link 2 to a suitable pilots operative control lever, not shown.

A throttle valve 59 controls an air inlet conduit 56 of an aircraft engine. The throttle valve 59 is controlled by a rod 60 operably connected as shown in the drawing to a throttle control arm 6 l.

The throttle control arm BI is keyed to a shaft 62 rotatably mounted in a bearing formed in the casing of the control unit as indicated at 63. R0-

Matter enclosed in heavy brackets I: ,1 appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

2 tatably mounted in the shaft 62 is one end of the shaft 4.

There is provided a servo piston 64 for operating the throttle 59 through shaft 62. The piston 64 is slidably mounted in a cylinder 65 having fluid pressure inlet passages 66 and 61 opening at opposite sides of the piston 64.

The piston 64 has a piston rod 68 pivotally connected at one end to the piston and atthe opposite end pivotally connected to an operating arm 69 formed integral with the rod 62.

Keyed to the pilots control shaft 4 is a second arm I0 connected through a link II to one end of a walking beam I2. The opposite end of the walking beam I2 is connected through a link I3 to the arm 69.

Pivotally connected at a point intermediate the opposite ends of the Walking beam 12 is one end of, a lever arm I4 which is alnxed. at the opposite end to a shaft I5.

The shaft I5 is rotatably supported in bearing portions I6 and II formed apart of the control unit. Freely rotatable on the shaft I5 is an arm I8. The arm I8 is pivotally connected at the free end to a rod I9 which connects the arm I8 to a piston 80. The latter piston is slidably mounted in a cylinder 8| into which opens at one end a passage 82 leading to a fluid pressure line such as oil under engine pressure. The piston 8|] is normally forced under pressure of the oil in an upward, direction as viewed, in the drawing.

A spring 83 is positioned between the piston and the upper end of the cylinder so as to force the piston in a downward direction upon oil pressure failure, whereupon the arm I8 is forced in a clockwise direction. An adjustable screw 84 projects through the arm I8 and is arranged so as to engage an abutment plate 85 on the arm I4 in the latter event so as to restrain movement of the arm I4 in a counterclockwise direction. A stop pin 86 projects from a portion 81 of the casing of the unit so as to restrain the arm I4 from movement in an opposite direction.

The pilots control lever may then effect manual control of the throttle valve 59 through shaft 4, arm I0, link II, walking beam I2, link I3, arm 69 and throttle control shaft 62.

The adjustable screw 84 is preferably adjusted so as to permit a small amount of angular travel of lever I4 between screw 84 and stop pin 86. During such manual operation of the throttle 59, lever arm I4 is driven between its restraining stops 84 and86 rotating shaft 15.

fixed an arm all-through which projectsan adjustable screw 89. The screw 89is arranged to engage a pin 90 which projects from an arm 9|, supported on shaft I5. The arm BI is freely rotatable on the shaft I5 and includes a second pin 92 which projects therefrom into a slot 93 formed in an arm 94 freely rotatable on a pin 95 projecting from one end of a shaft 96. The shaft 95 is supported in a bearing 9'l formed apart of the casing of the control and the shaft 96 may be rotatably adjusted as describedandclaimed in the copending divisional application-Serial No.

129,132, filed November 3, 1949, by Robert Z.

Hague and Howard A. Alexanderson and assigned to Bendix Aviation Corporation.

The arm 94 has an abutment plate 99 which bears-.uponone, end of. a-plunger I00. slidably suported by bracket portions "II and biased in an upward direction by spring I02. Lever arm 94 is driven by pin 92 of arm 9| so as to move plunger I00.

The plunger I is arranged so as to operably contactat I02one end of a valve stem I03 which is biased under force of'a'leaf spring I04 in an upward direction. A valvestem I03 has valve memberst05 and I06 .arranged so as to control passages 56 and 51 respectively opening into valve chamber I01. and leading to chamber 65 at opposite sides of-piston'fl so as to. control the movement of thepiston 64. The'fluid pressure line 82 op'ensintermediatethe.openingsof passageszfisland sun valve chamber I0I'. A fluid medium outlet or .drain passage I08 .alsoopens from" thevalve'v chamber I01 at the upper and lower sidesv of valves I 05 and I 06 respectively.

Another valve chamber H0 is providedseparated from the valve chamber I-01-rbya sealing member I. Projecting through the sealing member: I'II Isa valve stem II2. vAt. the lower end of the valve stem H2 is mounted a cylindricalvalve II3 having a spring II4 which tendsto bias the valve 3 and stem I I2 in an upward direction.

-Thefluid.pressurepassage 82 opens into the valvechamber H0 at the upper side of the valve I-I 3- so that during normal operation the fluid pressure medium forces the valve II3 downward into' -the position show'n in. the drawing. The exhaust assage I08 has a port II5 opening into the-housing of thecontro'l un'itA and a portv I I6 opening into the chamber IIO but closediby the valve II3 when biased downward to the position shown in' the drawing. A main drain passage II"| opens "into. the 'valvechamber II0. During-normal operation the fluid medium .is drainedfrom the housing by suitable ports not shown. v n

f When-nopressur'e mediumis available or upon oil pressure failure the drain valve II3 which is loaded by spring I is movedin an u'pward'di recuqn underforce of the springI I4 serving two purposes. It causes the oil in the housing of the control unit A to drain to a'predetermined low level by uncoveringa drain port I I6 so as: to perniit such drainage throu h port 'I I5, passagems, port" H6, valve chamber l I g and through passage I II-to the fluid outlet. Secondly the spring I I r s. v va te I I upw d i 't f o ti relat'on with the lower end of the valve stem I03 was o actuate the valve stem I03i'n*"an upward During such' fluid pressure" failure, I movement of e ilots ontr l l z ia t m re "am 10 in acounter clockwise directionf-causes' mova ment in a counter clockwise direction 'of the leverarm I4 between its restraining stops 86 and 84 whereupon valve stem II2 under force of spring II3 causes servovalve to move from its neutralposition as shown in the drawing, to an upper position so as to uncover the ports leading to passages 69 and 61 so as to permit movement of the throttle 59 manually. Similarly upon movement of the lever arm I4 in a clockwise direction'bet'ween its restraining stops 84 and 96 as upon manual movement of arm I0 in a, clockwise direction lever arm 94 actuates through plunger I00 the valve stem I03 in a downward direction opening the ports to passages 96 and 61. It will be seen from the foregoing that the manual operation of the servovalve I03 not only permits the opening of the passages 65 and 61 so that the, manual operation of arm 69 and accordin ly throttle 59 may be eifectedbut in the event slight pressure be available such movement of the valve I03 directs such slight pressure so as to effect piston 64 so as to assist the manual movement of the arm 69 and thereby assist in the manualcontrol of throttle valve 59. v

The latter feature of effecting manual control of the position of the throttle upon pressure failure is described and claimedin the co-pending patent applicationSerial No. 596,472, filed May 29, 1945, by Howard A. Alexandersonand Robert Z. Hague and assigned to Bendix Aviation Corporation.

AUTOMATIC CONTROL OF THROTTLE 7 When fluid pressure is available in excess of a predetermined value, the piston .80 is moved upward under the pressure medium from passage 82 against the force of spring 83. This latter action forces'link I9 upward moving lever I8 in a counter-clockwise direction so as to permit lever. arm I4 to move free of the restraining screw 84. Likewise upon such fluid pressure medium becoming effective the valve I I3 is moved downward against spring II4 permitting the servo-valve I03 to move free of the valve stem 2 under automatic control.

In order to effect the latter automatic control there is provided 'a'pressure responsive bellows assembly including an evacuated bellows IZI' supported at one end by a stud I22 carried bya portion I23 of the control unit A.

A spring I 24 is positioned within the evacuated bellows IZItending to expand the same. At the opposite end of the bellows I2I there is provided a/movable plate I25 interposed between the bellows I2I and a second bellows I26. The bellows I26 is mounted at the opposite end by a portion I2I of the control unit A.

. A passage. I29 formed in the control unit leads from the interior of the bellows I29 to a conduit which leads to the air intake manifold conduit'of the enginenot shown herein. Thus the bellows I26 is controlled by the intake manifold pressure of the engine which is in turn affected b the position of the throttle valve 59.

The movable plate I25 between the manifold pressurebellows I29 and evacuatedbellows. I2I isconnected through a link ,I3I, leaf springfl32, beam'I'33and the leaf spring 'I0,4 to the servovalve I03. Beam I33 in the schematic drawing contains at opposite ends the preloaded leaf springs I04 and I 32 which permit deflection of the servo-valve I03 by plunger I00 7 and valve stem I-I2 withoutexcessively loading the bellows assembly. The beam I33 may however be made in the form of a solid beam and link [3 I provided with a preloading mechanism which maintains the link l3l at a fixed length.

The selected pressure or datum of the bellows assembly may be changed by moving a pin [34 on which beam [33 is pivotally supported. Pin I34 is adjusted through operation of suitable mechanism, such as disclosed and claimed in the copending parent application Serial No. 596,472, filed May 29, 1945, by Howard A. Alexanderson and Robert Z. Hague and assigned to Bendix Aviation Corporation.

It will be readily seen however from the foregoing that upon an increase in the intake manifold pressure above the selected pressure there will result an expansion of the manifold pressure bellows I26 causing the beam I33 to be shifted in a clockwise direction whereupon the servovalve I03 will be adjusted upward causing a pressure medium to be applied through the passage 66 to the upper side of the piston 64 and exhausting the lower side through passage 61. This action will cause the piston 54 to be adjusted downward so as to adjust the arm 69 in a counter-clockwise direction moving valve 59 of the drawing through rod 60 in a valve closing direction decreasing the intake manifold pressure until the valve I03 is returned to a neutral position. An opposite effect is of course produced upon the intake manifold pressure dropping below the selected value.

A conduit 282 leads from the piston chamber 8| for providing a fluid medium for further controlling the induction pressure through operation of suitable mechanism, while conduits 66A and 82A also lead to mechanism affecting the latter control as described and claimed in the copending parent application Serial No. 596,472, filed May 29, 1945, by Howard A. Alexanderson and Robert Z. Hague and divisional application Serial No. 111,896, filed August 22, 1949, by Howard A. Alexanderson and Robert Z. Hague and which applications are assigned to Bendix Aviation Corporation.

In the event of a hydraulic pressure failure the novel manually operable mechanical linkage 10, H, 12, 73 and 14 is arranged so as to provide direct manual throttle control as heretofore explained. This linkage is particularly effective at the time of starting the aircraft engine. The manual throttle travel is sufficient to give normal power at take-off engine speed at sea level.

Although only one embodiment of the invention has been described and illustrated in detail, it is to be expressly understood that the same is not limited thereto. Various changes may be made in design and arrangement of the parts illustrated, as will be apparent to those skilled in the art. For a definition of the limits of the invention, reference should be had to the appended claims.

What is claimed is:

1. The combination comprising a first rotatable shaft, a second rotatable shaft, a walking beam operatively connecting said first and second rotatable shafts, stop means for limiting movement of said walking beam in a first sense and permitting movement of said walking beam in a second sense so as to drivingly connect said first and second rotatable shafts, and means for placing said stop means out of said limiting relation so as to permit movement of said walking beam in said [second] first sense.

2. The combination defined by claim 1 in which said first rotatable shaft is concentrically mounted relative to said second rotatable shaft.

3. The combination defined by claim 1 including a spring biased servo piston for operating said stop means.

4. The combination defined by claim 1 including a hydraulic motor means for rotatably positioning said [first] second shaft, and a spring biased servo piston for operating said stop means to drivingly connect said [motor means] first shaft to said second shaft through said walking beam upon the hydraulic pressure of the operating medium for said motor means [exceeding] decreasing below a predetermined value.

5. The combination comprising a first rotatable shaft, a second rotatable shaft concentrically mounted relative to said first shaft, a walking beam, first linkage means connecting one end of the walking beam to said first rotatable shaft, second linkage means connecting the opposite end of the walking beam to said second rotatable shaft, an arm pivotally supporting said walking beam at a point intermediate said opposite ends, said [arms] arm movable for permitting free movement of said first shaft relative to said second shaft, a second arm for locking said first mentioned arm from the latter movement while permitting pivotal movement of said walking beam relative to said first arm so as to drivingly connect said first rotatable shaft to said second rotatable shaft.

6. The combination defined by claim 5 including a hydraulic motor means for positioning said second rotatable shaft, a piston operatively connected to said second arm, a common hydraulic pressure source for operating said piston and motor means, said piston biased to a first position to cause said second arm to release said first mentioned arm upon the hydraulic operating pressure exceeding a predetermined value. and a spring for biasing said piston to a second position to cause said second arm to lock said first arm upon failure of the hydraulic operatin pressure.

'2. The combination comprising a first rotatable shaft, a second rotatable shaft, a walking beam, first means connecting said walking beam to the first and second shafts, a motor operatively connected to said second shaft, a control means for said motor, second means connecting said walking beam to said control means, said walking beam movable in a first sense for actuating said control means so as to effect movement of said second shaft by said motor, and said walking beam movable in a second sense for drivingly connecting said first and second shafts, means for limiting movement of said walking beam in said first sense so as to effect movement of said walking beam in said second sense and thereby drivingly connect said first shaft to said second shaft, and means for placing said limiting means out of operative relation so as to discontinue the driving relation between said first and second shafts.

HOWARD A. ALEXANDERSON. ROBERT Z. HAGUE.

REFERENCES CITED The following references are of record in the file of this patent or the original patent:

UNITED STATES PATENTS Number Name Date 1,625,563 Payne Apr. 19, 1927 2,392,565 Anderson Jan. 8, 1946 2,431,590 Smith Nov. 25, 1947 

